Ultrasound tissue characterization Methods of assessing the Achilles tendon for tendinopathy continue to be debated. Common methods include ultrasound and magnetic resonance imaging [Khan][Astrom]. A novel assessment tool is ultrasound tissue characterization (UTC) which uses ultrasound to quantify tendon structure [van Schie][Docking-2015][Docking-2016][Rosengarten][Bedi].